Having Gortash survive the brain would be nice for the control ending. Let him see you betray him and then tadpole him, turning him into just another thrall.
I seriously love that idea. That'd be such a gigachad move to enthrall the very person who enthralled countless others. Nothing but a mindless meat-puppet serving our own cause, brilliant!

It's such a perfect asshole move for a Durge because Gortash really wants to share, and you promise, and then in the end you remind him who you are. Maybe he should have stuck with Orin.
Bane's crying in a corner.